The invention relates generally to desalination systems and methods for water recovery. More particularly, this invention relates to desalination systems and methods using ion exchange membranes for silica removal and water recovery.
In industrial processes, large amounts of wastewater, such as aqueous saline solutions are produced. Generally, such wastewater is not suitable for direct consumption in domestic or industrial applications. In view of the limited eligible water sources, it is desirable to recover eligible water from the wastewater.
There have been attempts to remove silica from the wastewater or other water sources containing silica. For example, streams containing silica are introduced into desalination apparatuses, such as reverse osmosis apparatuses while pH of such streams is increased for silica removal because higher pH of the streams results in higher ionization of silica. However, such processes suffer from complicated and rigorous pretreatment requirements and high cost. Typically, fluctuation and inefficiency of the pretreatment may cause scaling or fouling of sparingly soluble salts, such as magnesium hydroxide or calcium carbonate within the silica removal apparatuses, which is disadvantageous for silica removal and the silica removal apparatuses.
Therefore, there is a need for new and improved desalination systems and methods for silica removal and water recovery.